Heller tossed five changeups in 2019 to bring his career total to 53. It averages 85.1 mph at 1473 RPM, leading to a career 22.6% SwStr%, 41.2% O-Swing%, and .182 BAA.
Heller’s fastball averaged 93.2 mph in 2019, down considerably from the 94.8 he averaged in 2017 pre-Tommy John surgery. It generated zero whiffs and three chases in 2019, but a .222 BABIP and .000 ISO led to a 1.4 pVAL.
His primary strikeout pitch, Heller’s slider averaged 83.2 mph and 2393 RPM in 2019, en route to a 25.0% SwStr% and six strikeouts on the 11 plate appearances it ended. This was bouyed by the 10% O-Contact on its 35.7% O-Swing rate, but one home run in the small sample pushed the pVAL to -0.5.
Heller’s fastball has a ton of arm side run on it. At 95 mph, it generates a lot of weak contact. Last season, hitters hit the pitch into the ground 52.7% of the time, leading to a .200 batting average and a 1.7 pVAL. He will need to throw more strikes (20% walk-rate) in order to see any more success however.
Heller’s curveball absolutely mystified hitters in 2017. He saw a 46.7% chase rate, compared to only an 18.8% zone swinging rate. Hitters only made contact a lowly 39.1% of the time, leading to a 23.7% swinging strike rate and a 36.4% strikeout rate. As long as Heller continues to bury this pitch out of the zone while he is ahead in the count, he will continue to see success with it.
Heller only threw his changeup 29 times in 2017. He used it primarily to try and get hitters to chase, as evidenced by his 31% zone rate. It worked, as hitters bit 40% of the time on balls out the zone. This led to a 27.6% swinging strike rate.